Underwater exploration device

ABSTRACT

There is disclosed a smoke generator for use on underwater exploration devices. Upon descent of the exploration device, the smoke generator is automatically armed when hydrostatic pressure increases to a predetermined level. Upon ascent, the smoke generator is automatically triggered when hydrostatic pressure decreases to a predetermined level.

Unite States 11 1 1111 3,898,609

Charles Aug. 5, 1975 [5 UNDERWATER EXPLORATION DEVICE 3,066,324 12/1962Snyder 81'. al. 9/8 R 3,196,789 7/1965 Fasig etal 102 7 [75] Inventor?Charles Brest France 3,762,327 10/1973 Murray et al. 102 90 X [73]Assignees: Centre National pour lExploitation des Oceans (CNEXO); LeNickel,

both of Paris, France; P interest Primary Examiner-Richard A. Farley toeach Attorney, Agent, or Firm-Fleit & Jacobson [22] Filed: Nov. 21, 197321 Appl. No.: 417,939

[57] ABSTRACT [30] Foreign Application Priority Data Nov. 21, 1972France 72.41224 There IS disclosed a smoke generator for use on un- 52us. (:1 340/4 R; 9/8 R; 102/90 derwater exploration devices descent ofthe 51 Int. Cl. G08b 5/40 Plomtio device the Smoke generator isautomatically [58] Field of Search 340/4 102/9O 7 armed when hydrostaticpressure increases to a predetermined level. Upon ascent, the smokegenerator is automatically triggered when hydrostatic pressure de- [56]References Cited creases to a predetermined level.

UNITED STATES PATENTS 3,048,] 11 8/1962 Baker et al. 102/54 X 11 Claims,3 Drawing Figures PATENTED 5|975 3,898,609

FiGj

1b H63 3a 3.2 36 34 35 a1 UNDERWATER EXPLORATION DEVICE This inventionrelates to underwater exploration devices.

lt is known that, in exploring sea-beds, the devices used are, forexample, photographic devices or sampling devices, and are frequently ofthe type referred to as free-fall which means that they are releasedfrom a ship to which they are not linked. Being secured to ballast andto floats, the free-fall devices sink in the water under the action ofthe ballast, and then contact the sea-bed whereupon the ballast isreleased and the taking of photographic pictures or the collection ofsamples is initiated by means of a variety of automatic devices whichwill not be described herein since they do not form part of the presentinvention. Then, under the action of the floats, the devices rise to thesurface to be retrieved.

The ship entrusted with the retrieval of the devices, which is usuallythe launching ship, is commonly far from the exploring devices at theinstant when they surface, and it is necessary that the devices shouldbe equipped with marking means which allows their detection from adistance. These marking means are of several kinds, including radiobeacons, flashing light generators, inflatable balloons, and smokegenerators. The present invention specifically relates to marking meansof the last-mentioned kind.

One of the objects of the invention is to produce a submersible smokegenerator which will give off smoke automatically when it reaches thesurface of the water after having descended to and returned from theseabed.

Another object of the present invention is to provide an apparatus ofthis kind which is watertight up to depths of as much as 6,000 metres.

A further object is to provide an apparatus of this kind which offersgreat operational reliability and in particular is protected againstaccidental actuation, for example upon being dropped overboard.

A complementary object of the invention is to provide a smoke generatorin which smoke discharge does not occur until the apparatus has actuallyreached the surface of the water.

Another object of the invention is to provide an apparatus of this kindwhich may easily be assembled and dismantled, and which lends itself tonumerous consecutive operations.

In accordance with the invention there is provided an underwaterapparatus of the smoke generator kind, comprising a generallycylindrical body; a firing control device arranged in the cylindricalbody to adopt an idle position and an actuating position; means forinfluencing the firing control device when an external hydrostaticpressure is exerted on the underwater apparatus and for causing thefiring control device to shift from the idle position to the actuatingposition when the external hydrostatic pressure is reduced virtually tozero; means for igniting a smoke-producing compound in the cylindricalbody when the firing control device is shifted to the actuatingposition; smoke discharge means; and means for plugging the dischargemeans while the smoke-producing compound remains unignited and foropening the discharge means when the compound is ignited.

The firing control device preferably comprises a metal priming cylinderwhich slides within an insulating sleeve in said cylindrical body andwhich is displaceable between a standby position in engagement with anabutment formed within the sleeve and an actuating position inengagement with a metal disc which is mounted within but electricallyinsulated from the cylindrical body; an elastic element arranged to urgethe priming cylinder towards the idle position; a firing cartridgeconnected electrically at one end to the cylindrical body and arrangedto be connected at the other end to one terminal of an electric cell;and means for connecting the other terminal of the electric cell to thepriming cylinder.

The elastic element specified in the preceding paragraph advantageouslycomprises a metal tension spring firmly joined at one end to the primingcylinder, and at the other end to a second metal disc which abutsagainst a shoulder formed in the insulating sleeve.

In this case, the means for connecting the other terminal of theelectric cell or battery electrically to the priming cylinder comprisethe metal tension spring paired with a connecting wire, and a metalcompression spring arranged between the second metal disc or washer andthe other terminal of the electric cell. This compression spring alsoserves the purpose of urging the cell against the firing cartridge andof holding the second metal disc against its shoulder.

The said means for influencing the firing control device preferablycomprise a sleeve screwed to the end part of the cylindrical body andhaving an axial bore with an external conical recess; a control pinslidingly mounted in the axial bore of the sleeve and terminating in aconical part projecting towards the inside of the cylindrical body; tworesilient blades joined together along the greater proportion of theirlength and which are firmly joined at their one ends to the firingcontrol device and spread apart in Vee-shape at their other ends closeto which they are formed with openings in which the projecting ends ofthe conical part are held; and an elastic cover which caps the sleeveand the corresponding end of the cylindrical body and which, when underthe action of external pressure, is arranged to assume the shape of theconical recess of the said sleeve and to urge the control pin inwards,said control pin being firmly joined to the said elastic cover, forexample by overmoulding.

It will be understood that, when the smoke generator apparatus inaccordance with the invention sinks towards the sea-bed, the hydrostaticpressure exerted on the elastic cover holds the cover against theconical recess of the sleeve screwed to the extremity of the cylindricalbody and, at the same time, urges the control pin towards the inside ofthe assembly. The projecting cone of this pin is then engaged betweenthe resilient blades without the remainder of the firing control deviceshifting from the idle position.

While the apparatus is rising towards the surface of the water afterrelease of the ballast, as mentioned above, no smoke is generatedbecause, under the action of the external pressure, the elastic covercontinues to hold the control finger in position. However, when theapparatus reaches the surface or just before it reaches the surface, thehydrostatic pressure drops virtually to zero, and the elastic coverregains its initial form and withdraws the control pin which pulls onthe blades in which it is caught whilst drawing the firing controldevice towards its actuating position. The smoke-producing compound isthen ignited, as will subsequently be described, and discharge of smokebegins.

It is thus clear that the smoke is discharged automatically when theapparatus returns to the surface, without the need of an externalcontrol device.

Suitably, the elastic cover mentioned above is formed in its planeexternal surface with a retaining groove wherein is inset a rigidprotective plate formed with at least one hole. Any accidental actuationupon being dropped into the water is thus rendered virtually impossible:if a pressure is exerted inadvertently on the actuating end part of theapparatus in accordance with the invention, the rigid protective plateprevents transmission of this pressure to the control elements.

In one form, the smoke discharge device comprises a metal cover cappingthe corresponding end of the cylindrical body; an elastic cover cappingthe said metal cover and a part of the cylindrical body; and anapertured cup-like member which is arranged with its base facinginwardly of the cylindrical body, and with the interpositioning of atoroidal sealing joint, between the charge of said smoke-producingcompound and the said metal cover.

Thus, the smoke produced by the smoke-producing compound escapes throughthe orifice of the cup-like member after having pushed back the metalcover and the elastic cover which cap that end of the apparatus.

The means of igniting the smoke-producing compound when the firingcontrol device shifts to the actuating position preferably comprise apyrotechnic delay device such as a slow fuse installed in an axial tubeextending from the firing cartridge towards the smokeproducing compound;a pyrotechnic connecting element and an intermediate combustiblecompound between the fuse and the smoke-producing compound; means ofconnecting the space situated between the slow fuse and the axial tubeto a toroidal groove located within the cylindrical body; a sealingmember outwardly sealing off the toroidal groove; and an elastic sleevesurrounding the cylindrical body at either side of that sealing member.

This arrangement enables gases released by the combustion of the slowfuse to escape outwards, which is important for uniformity ofcombustion. The function of the slow fuse is to create a delay betweenthe instant at which the firing action is triggered and that at whichthe discharge of smoke begins. In fact, the firing action occurs alittle before the apparatus has risen to the surface, and it isappropriate to prevent the ignition of the smoke-producing compoundunder water, in order to eliminate the risk of quenching. Finally, theintermediate compound serves the purpose of assisting the ignition ofthe smoke-producing compound.

The cylindrical body is advantageously constructed in two parts whichare inserted into a cylindrical coupling member with theinterpositioning of a sealing joint or packing, these two parts beingheld in position by means of a nut screwed between them. It will beappreciated that this arrangement eases the assembly and dismantling ofthe apparatus in accordance with the invention, which may be used againafter replacement of, for example, the pyrotechnic compounds.

An embodiment of the present invention will now be described, by way ofexample, with reference to the accompanying drawings in which:

FIG. 1 shows one end part of smoke-generator apparatus according to theinvention, in longitudinal section;

FIG. 2 shows the central portion of the apparatus, also in longitudinalsection; and

FIG. 3 shows the other end part of the apparatus, again in longitudinalsection.

The submersible smoke-generator apparatus in accordance with theinvention is illustrated in three parts in the drawings. In each Figureof the drawings, the elements have been denoted by the same referencenumerals.

Referring to the drawings, the smoke-generator apparatus comprises acylindrical body formed in two parts 1a and lb and made of a metalresistant to corrosion by water, such as an aluminium alloy containingmagnesium. Actuating elements are denoted generally by reference 2 inFIG. 1, reference 3 denotes an electric cell or battery (FIG. 1), and acharge of smokeproducing powder 4 is shown in FIGS. 2 and 3. Elementsfor discharging the smoke produced by the powder charge 4, after firing,are denoted generally by reference 5 in FIG. 3. To simplify thedescription, the terms actuating end will be applied to that part whichis illustrated in FIG. 1, and the term smoke discharge end will beapplied to that part which is illustrated in FIG. 3. The terms inside"and outside are used to refer to the inside and outside of the apparatusas a whole.

The actuating elements 2 comprise a guide sleeve 6 which has an outerconical recess and which is screwed into the end of body part 1a. Thesleeve 6 has an axial bore within which a pin 7 is slidingly mounted.Towards the outside, the pin 7 has its head secured to an elastic cover8, preferably of vulcanised rubber such as NEO- PRENE, which caps theguide sleeve 6 and the extremity of the cylindrical body la. On itsouter surface, the cover 8 is provided with a protective metal disc 9having a central hole and held within a groove formed in the cover 8.

Towards the inside, the pin 7 terminates in a projecting conical part 10the apex of which is located within a V-formed at the extremity of twocoupled blades 11. An opening 12 is formed in each of these blades,close to where they are bent outwardly to form a V and the size of theseopenings is such that, when the conical part 10 of the pin 7 is forcedbetween the blades 11, thus spreading the blades apart, the base of thecone is caught in the openings 12.

Inside the cylindrical body part 1a, a metal contact disc or washer 13is gripped between the end of the guide sleeve 6 and an insulatingsleeve 14 as will hereinafter be described. The blades 11 are mounted ona metal priming cylinder 15 which can slide within the insulating sleeve14, between the contact disc or washer 13 and a first shoulder orabutment formed within the sleeve. This cylinder 15 is urged away fromthe contact disc 13 by a tension spring 16 which is anchored on a metaldisc 17 held against a second shoulder formed in the sleeve 14. Towardsthe smoke discharge end, the sleeve 14 also contains the electric cellor battery 3 whose positive terminal is pressed into engagement with acontact screw 18 by a spring 19 interposed between the base of the cell,that is its negative terminal, and the metal disc 17.

Moving towards the smoke discharge end of the apparatus, a cartridge 20is provided with a filament 21 which is connected at one end to thecontact screw 18 and at the other end to the metal casing of thecartridge 20. The insulating sleeve 14 bears against a second shoulderformed within the body part 1a, with the interpositioning of a toroidaljoint packing-14a. The disc 17 is held in position by the tension spring16 and by the compression spring 19, the latter spring also acting tohold the cell 3 fast in its housing. The method of securing thecartridge 20 and its contact screw 18 will subsequently be described.

The operation of this actuating system is as follows. When thesmoke'generator apparatus sinks below the surface of the water, thehydrostatic pressure pushes the elastic cover 8, protected by the metaldisc 9 against any accidental action, into the conical recess of thesleeve 6, and this moves the conical part 10 of the pin 7 between theblades 11 where it is caught, as has been stated above.

When the apparatus rises to the surface again, the reduction of thepressure on the elastic cover 8 causes the pin 7 to slide outwards as todraw the blades 11 and the priming cylinder 15. The priming cylinderthereupon comes into contact with the metal disc 13, so that theelectrical circuit incorporating the cell 3 is closed. Starting from thenegative terminal, this circuit comprises the spring 19, the spring 16paired with a connecting wire which is not illustrated, the cylinder 15,the disc 13, the cylindrical body part 1a, the filament 21, and thecontact screw 18.

The flow of current through the filament 21 heats the filament to thepoint of incandescence which ignites the cartridge 20 which, in turn,ignites the smokeproducing powder.

Referring now to the smoke-generating part, the elements are illustratedin FIGS. 2 and 3 and comprise the cylindrical body part lb mounted onthe body part la by means of a nut 22 and a coupling element 23. Moreparticularly, the body 1a receives the coupling element 23 with theinterpositioning of a toroidal joint or packing 24 and a sealing washer,and the nut 22 between the body parts la and lb holds the whole inposition; the nut 22 has a shoulder which bears on the end of the bodypart la. The connection between these parts is shielded by a sleeve 25of a synthetic material such as Neoprene.

The cartridge 20 is screwed into the coupling element 23 at theactuating end side of the latter.

The coupling element 23, which has an axial through opening, is also provided with vent holes 26 connecting its axial opening to a groove 27formed at the end and in the inner surface of the nut 22. A metal washer28 closes this groove 27 and bears at its other side against a shoulderor abutment formed in the sleeve 25.

A slow fuse 29 connects the cartridge 20 to the smoke discharge end partof the apparatus, passing through an axial tube 30 which penetrates intothe bore of the coupling element 23 and which is firmly joined to thatelement. The smoke-producing charge 4 is situated between the tube 30and the body part 1b.

The smoke discharge elements 5, illustrated in FIG. 3, comprise a metalcover 31 which caps the extremity of cylindrical part 1b. The cover 31itself is capped by a cover 33 which is made of a synthetic materialsuch as NEOPRENE and which also covers a part of the body part lb. Awasher 34, in the form of an axially apertured cup, is arranged with thebase facing the body part 1b between the smoke-producing charge and thecover 31, with interpositioning of a toroidal joint 35.

Referring to FIG. 3, which shows the extremity of the slow fuse 29 andthe tube 30, an intermediate combustible mixture 36 fills the extremityof the body part lb. A connecting pyrotechnic element 32 ensures thepropagation of burning between the slow fuse 29 and the intermediatemixture 36.

The operation of the smoke discharge system is as follows. Ignition ofthe cartridge 20 which occurs as has been stated above, effects theignition of the slow fuse 29 passing into the tube 30. The gasesreleased by the combustion of this fuse may escape outwardly through thepassages 26 by pushing back the washer 28 and the elastic sleeve 25.

The slow fuse ignites the connecting pyrotechnic element 32 which, forits part, ignites the intermediate compound 36 and, in this case too,the combustion gases may escape as has been stated, by passing throughthe space present between the tube 30 and the slow fuse 29.

The intermediate compound 36, for its part, ignites the smoke-producingcharge 4, and the smoke thus produced and passing through the orifice ofthe washer 34, causes the covers 31 and 33 to be blown off. The smokethen discharges from the apparatus. This smoke discharge renders itpossible to locate the position of the smoke generator apparatus fromafar, and thus easily retrieve the associated underwater explorationdevice.

What we claim is:

I. An underwater apparatus of the smoke generator kind, comprising agenerally cylindrical body; a resilient cap sealing one end of saidbody, firing control means arranged in the cylindrical body connectedwith said resilient cap to be acted upon by hydrostatic pressuretransmitted through said cap, said firing control means being arrangedto adopt a repose position, an idle position, and an actuating position;actuating means for influencing the firing control means responsive to apredetermined external hydrostatic pressure exerted on the resilient capto cause the firing control means to shift from the repose position tothe idle position, and to shift from the idle position to the actuatingposition responsive to the external hydrostatic pressure being reducedvirtually to zero; ignition means for igniting a smoke-producingcompound in the cylindrical body responsive to the firing control devicebeing shifted to the actuating position; smoke discharge means; pressuredetachable means for plugging the discharge means while thesmoke-producing compound remains unignited and for detaching from andopening the discharge means responsive to pressure being generated whenthe smoke producing compound is ignited, and protective means protectingsaid firing control means from accidental actuation.

2. An apparatus according to claim 1, in which said firing controldevice comprises a metal priming cylinder which slides within aninsulating sleeve in said cylindrical body and which is displaceablebetween a standby position in engagement with an abutment formed withinthe sleeve and an actuating position in engagement with a metal discwhich is mounted within but electrically insulated from the cylindricalbody; an elastic element arranged to urge the priming cylinder towardsthe idle position; a firing cartridge connected electrically at one endto the cylindrical body and arranged to be connected at the other end toone terminal of an electric cell; and means for connecting the otherterminal of the electric cell to the priming cylinder.

3. An apparatus according to claim 2, in which said elastic elementcomprises a metal tension spring anchored at one end on said primingcylinder and at the other end connected to a second metal disc whichabuts against a shoulder formed in said insulating sleeve, said meansfor electrically connecting the other terminal of the electric cell tosaid priming cylinder comprising said metal tension spring and a metalcompression spring located between said second metal disc and the otherterminal of the electric cell and also arranged to urge the electriccell against said firing cartridge and to hold said second metal discagainst its shoulder.

4. An apparatus according to claim 3, in which said insulating sleeve islocated in said cylindrical body, at one extremity by said metal discwhich is screwed into the cylindrical body, and, at the other end, bymeans of a toroidal joint urged against a shoulder formed in thecylindrical body.

5. An apparatus according to claim 1 in which said means for influencingthe firing control device comprise a guide sleeve which is screwed intosaid cylindrical body and is formed with an axial bore having a conicalrecess at its outer end; a control pin slidably arranged in the axialbore of the guide sleeve and terminating inwardly of the cylindricalbody in a projecting conical part; two elastic blades joined togetheralong the greater proportion of their lengths, firmly joined at theirends to the firing control device, and spread apart in V shape at theirother ends, close to which the blades are formed with orifices arrangedto engage with the projecting conical part of said control pin; and anelastic cover capping the guide sleeve and the corresponding end of thecylindrical body and arranged to assume, under the action of externalhydrostatic pressure, the shape of the conical recess of the guidesleeve and to urge inwardly said control pin to which it is secured.

6. An apparatus according to claim 5, in which said elastic cover isformed in its plane external surface with a retaining groove whichreceives a rigid protective disc formed with at least one hole.

7. An apparatus according to claim 6, in which said elastic blades arefirmly secured to said priming cylinder.

8. An apparatus according to claim 7, in which the end of said guidesleeve screwed into the cylindrical body firmly engages said metal discto ensure electrical contact with the cylindrical body.

9. An apparatus according to claim 1 in which said smoke discharge meanscomprise a metal cover capping the corresponding extremity of saidcylindrical body, and an elastic cover capping said metal cover and apart of the cylindrical body.

10. Apparatus according to claim 1 in which said means for igniting thesmoke-producing compound when the firing control device is shifted tothe actuating position comprise a delayed pyrotechnic firing device anda device which is arranged to allow the discharge of the gases generatedby the pyrotechnic delay device and which comprises a toroidal grooveformed inside said cylindrical body and in communication with the saidpyrotechnic delay device, a sealing washer outwardly sealing saidtoroidal groove, and an elastic sleeve surrounding the cylindrical bodyat either side of the sealing Washer,

11. An apparatus according to claim 2 in which said cylindrical body isformed in two parts which are inserted into a cylindrical couplingmember with the interpositioning of a sealing joint, said two partsbeing held in position by means of a nut screwed between

1. An underwater apparatus of the smoke generator kind, comprising agenerally cylindrical body; a resilient cap sealing one end of saidbody, firing control means arranged in the cylindrical body connectedwith said resilient cap to be acted upon by hydrostatic pressuretransmitted through said cap, said firing control means being arrangedto adopt a repose position, an idle position, and an actuating position;actuating means for influencing the firing control means responsive to apredetermined extErnal hydrostatic pressure exerted on the resilient capto cause the firing control means to shift from the repose position tothe idle position, and to shift from the idle position to the actuatingposition responsive to the external hydrostatic pressure being reducedvirtually to zero; ignition means for igniting a smoke-producingcompound in the cylindrical body responsive to the firing control devicebeing shifted to the actuating position; smoke discharge means; pressuredetachable means for plugging the discharge means while thesmoke-producing compound remains unignited and for detaching from andopening the discharge means responsive to pressure being generated whenthe smoke producing compound is ignited, and protective means protectingsaid firing control means from accidental actuation.
 2. An apparatusaccording to claim 1, in which said firing control device comprises ametal priming cylinder which slides within an insulating sleeve in saidcylindrical body and which is displaceable between a standby position inengagement with an abutment formed within the sleeve and an actuatingposition in engagement with a metal disc which is mounted within butelectrically insulated from the cylindrical body; an elastic elementarranged to urge the priming cylinder towards the idle position; afiring cartridge connected electrically at one end to the cylindricalbody and arranged to be connected at the other end to one terminal of anelectric cell; and means for connecting the other terminal of theelectric cell to the priming cylinder.
 3. An apparatus according toclaim 2, in which said elastic element comprises a metal tension springanchored at one end on said priming cylinder and at the other endconnected to a second metal disc which abuts against a shoulder formedin said insulating sleeve, said means for electrically connecting theother terminal of the electric cell to said priming cylinder comprisingsaid metal tension spring and a metal compression spring located betweensaid second metal disc and the other terminal of the electric cell andalso arranged to urge the electric cell against said firing cartridgeand to hold said second metal disc against its shoulder.
 4. An apparatusaccording to claim 3, in which said insulating sleeve is located in saidcylindrical body, at one extremity by said metal disc which is screwedinto the cylindrical body, and, at the other end, by means of a toroidaljoint urged against a shoulder formed in the cylindrical body.
 5. Anapparatus according to claim 1 in which said means for influencing thefiring control device comprise a guide sleeve which is screwed into saidcylindrical body and is formed with an axial bore having a conicalrecess at its outer end; a control pin slidably arranged in the axialbore of the guide sleeve and terminating inwardly of the cylindricalbody in a projecting conical part; two elastic blades joined togetheralong the greater proportion of their lengths, firmly joined at theirends to the firing control device, and spread apart in V shape at theirother ends, close to which the blades are formed with orifices arrangedto engage with the projecting conical part of said control pin; and anelastic cover capping the guide sleeve and the corresponding end of thecylindrical body and arranged to assume, under the action of externalhydrostatic pressure, the shape of the conical recess of the guidesleeve and to urge inwardly said control pin to which it is secured. 6.An apparatus according to claim 5, in which said elastic cover is formedin its plane external surface with a retaining groove which receives arigid protective disc formed with at least one hole.
 7. An apparatusaccording to claim 6, in which said elastic blades are firmly secured tosaid priming cylinder.
 8. An apparatus according to claim 7, in whichthe end of said guide sleeve screwed into the cylindrical body firmlyengages said metal disc to ensure electrical contact with thecylindrical body.
 9. An apparatus according to claim 1 in which saidsmoke discharge means comprise a metal cover capping the correspondingextremity of said cylindrical body, and an elastic cover capping saidmetal cover and a part of the cylindrical body.
 10. Apparatus accordingto claim 1 in which said means for igniting the smoke-producing compoundwhen the firing control device is shifted to the actuating positioncomprise a delayed pyrotechnic firing device and a device which isarranged to allow the discharge of the gases generated by thepyrotechnic delay device and which comprises a toroidal groove formedinside said cylindrical body and in communication with the saidpyrotechnic delay device, a sealing washer outwardly sealing saidtoroidal groove, and an elastic sleeve surrounding the cylindrical bodyat either side of the sealing washer.
 11. An apparatus according toclaim 2 in which said cylindrical body is formed in two parts which areinserted into a cylindrical coupling member with the interpositioning ofa sealing joint, said two parts being held in position by means of a nutscrewed between them.